Porous CuCo2O4 microtubes as a promising battery-type electrode material for high-performance hybrid supercapacitors

Abstract

Hollow nanostructures of transition metal oxides (TMOs) with hollow interior, low density, large surface area and surface permeability have drawn significant interest as electrode materials for supercapacitors. However, it is still challenging to controllably prepare hollow nanostructures by a facile method. Herein, we report for the first time that CuCo2O4 microrod precursor obtained from a solvothermal method in ethanol media can be converted into porous CuCo2O4 microtubes (CuCo2O4 MTs) in the post annealing treatment. The results of electrochemical tests demonstrate that these MTs are categorized as the typical battery-grade electrode materials. They can deliver a high capacity up to 393.66 C g−1 at 1 A g−1 and still hold 305.99 C g−1 at 10 A g−1. Additionally, an assembled hybrid supercapacitor (CuCo2O4 MTs//AC HSC) exhibits 78.23 F g−1, good cycling durability and high energy density (32.49 W h kg−1 at 912.10 W kg−1). The present synthetic methodology may be further applicable to the preparation of other hollow structural TMOs with applications in high-performance energy storage and conversion devices.